Project Summary/Abstract Healthy pregnancy is rooted in normal placental development. Real time monitoring of placental function has been stymied by the lack of safe access to cells of the maternal-fetoplacental interface before birth. Endocervical sampling by cytobrush has been followed by immunobead separation of trophoblast for genetic and protein analyses; however, ploidy in these cells is incompletely understood and affects downstream molecular events. Although decidual cells have been documented in cytological samples during pregnancy, immuno-isolation to characterize these maternal placentation-specific cells has not been done. In this exploratory/developmental R21, a two-pronged maternal-fetoplacental approach to pregnancy health investigates both HLA-G positive invasive trophoblast and maternal decidual stroma obtained noninvasively from the mother?s cervix across gestation. Hypotheses are: normal pregnancy phenotype will differ from complicated pregnancy by a) chromosome copy number in endocervical trophoblast; b) viability of endocervical decidua. Specific aims are to investigate the relationship between pregnancy phenotype and chromosome copy number in endocervical invasive extravillous trophoblast, and to examine the feasibility of relating pregnancy phenotype to characteristics of endocervical decidual stroma. Pregnancies will be phenotyped by clinical, demographic, and outcome traits and examined in relationship to molecular data in endocervical cells of placental development. Immuno-fluorescent in situ hybridization and image cytometry will be conducted to develop chromosome copy number criteria (e.g., normal range and variation, sensitivity, specificity) in endocervical trophoblast. Immunostaining and assays for DNA integrity in decidual stroma from the endocervix will detect cell viability and potential for chromosome copy number studies.